(1) Field of the Invention
The present invention relates to a ceiling insert to which a hanging bolt or a hanging fittings can be simply and firmly mounted after a concrete is soldified. The ceiling insert is buried beforehand inside the concrete for a ceiling structure in a construction of concrete structure for buildings and the like.
(2) Prior art
The ceiling insert is a fittings which is buried when the concrete of a slab and a building frame is casted in building constructions inside a concrete forming a ceiling structure so as to enable a hanging bolt or other hanging fittings to be fixed with a screw later.
FIG. 12 is a vertical section showing a working condition of the conventional ceiling insert. The ceiling insert 52 buried beforehand inside the concrete 51 is provided with a female thread inside the insert. A hanging bolt 54 having male thread 55 was inserted into the female thread from the bottom and was fixed.
However, the screw fixing work of the hanging bolt 54 into the conventional ceiling insert 52 was done by placing the tip of male thread 55 of the hanging bolt 54 on the female thread 53 and by turning the hanging bolt 54 manually around its axis with pressure one by one. However, since the ceiling inserts 52 are buried and installed in a ceiling structure at about 900 mm interval lengthwise and crosswise, total number of the inserts is of numerous. Therefore, the mounting works of the hanging bolts 54 into the ceiling structure took much time, and had problems of having extremely bad working efficiency.